Modular dry-air evaporative cooler

ABSTRACT

Air conditioning apparatus for the sensible cooling of useable air by the evaporative process at a cost of operation substantially lower than that of mechanical refrigeration of the same capabilities, and advantageously comprised of modular evaporator and blower units and multiple stages thereof with the use of substantially permanent inexpensive plastic materials conducive to the efficient absorption of heat between separate columns of air, one column subject to the evaporative cooling process with no energy change, and the other column subject to the sensible cooling process with a subtraction of energy from the useable air.

Umted States Patent 1 1 1111 3,877,244 Di Peri 1 Apr. 15, 1975 [54]MODULAR DRY-AIR EVAPORATIVE 3,363,680 1/1968 Baker 165/180 COOLER3,435,893 4/1969 Withers. 165/180 3,438,432 4/1969 Wetch 165/180 [76]Inventor: Leonard J. Di Peri, 18325 Lahey Northndge, Cahf' 91324 PrimaryExaminer-William J. Wye [22] Filed: June 11, 1973 211 App]. No.2 368,756[57] ABSTRACT Air conditioning apparatus for the sensible cooling ofuseable air by the evaporative process at a cost of op- [52] US. Cl.62/314; 62/311, 62/314, eration Substantially lower than that ofmechanical 1 I 1 165/180 frigeration of the same capabilities, andadvanta- [5 1 C -f g y comprised o modular ap ato and o e [58] 0 Searchl 3 165/180 units and multiple stages thereof with the use ofsubstantially permanent inexpensive plastic materials con- [56]References C'ted ducive to the efficient absorption of heat between sep-UNITED STATES PATENTS arate columns of air, one column subject to thcevapo- 2,165,979 7/1939 Nicholson 62/311 rative cooling process with noenergy change, and the 0? 10/1940 ey oefcr 62/314 other column subjectto the sensible cooling process 2,259,541 10/1941 Ballard 62/314 with asubtraction of energy from the useable air, 2,725,729 12 1955 M111562/314 3,214,936 11/1965 Di Peri 62/314 23 Claims, 9 Drawing gur sPATENTEDAPR 1 sl'zs 3,377, 244 sum 1 5 3 FIG. 1.

PATENTEDAPR 1 SETS 3' 77, 2411 sum 3 95 3 MODULAR DRY-AIR EVAPORATIVECOOLER BACKGROUND Reference is made to my US. Pat. No. 3,214,936entitled DRY-AIR EVAPORATIVE COOLER issued Nov. 2, 1965 wherein there isa separation of air into two columns, one column subject to evaporationand the other an isolated column of useful air subject to sensiblecooling. The unit construction and materials employed in the fabricationof said patented cooler has limited use and is not the least costly. Asto use, said patented cooler and others of the prior art are each of adetermined capacity and require specified design for specificinstallations. And as to materials of construction, they have beenfabricated of metals, reference being made to the heat transfer tubeswhich are presumably metallic for efficient heat transfer. However, aswill be hereinafter disclosed, the presumptive use of metals of highthermal conductivity is not necessarily required in heat transfer meansof the type under consideration; and on the contrary it has beendiscovered that efficient evaporative modules with sensible air passagesare advantageously fabricated of plastic materials which have lowerthermal conductivity as compared, for instance, with aluminum or copper.Therefore and in accordance with this invention, I provide modularcomponents for the construction of air cooler installations tospecification as circumstances require, and of durable inexpensivematerials. With the present invention, there is economy in bothinstallation and operation, while satisfying the temperature droprequirements as desired.

The construction and installation of prior art evaporate coolers hasbeen made according to specification requirements, with the coolingcapacity or cubic foot per minute capacity in mind. Also, with ordinarysimple evaporative units (not compound) the temperature drop is notentirely predictable and not altogether controllable. On the contrary, awide range of predicted controllability is aforded with mechanicalrefrigeration, but at great expense both in high installation costs andhigh operation costs. In fact, there is such a vast difference in thenormal capabilities of evaporative cooling as compared with mechanicalrefrigeration cooling, that evaporative cooling is seldom if everconsidered for use where precisely controlled high temperature drop withabsolute humidity is a requirement. However, with the present invention,predictably high temperature drop is controlled in a dry-air evaporativecooler, utilizing separated columns of evaporative cooled air andsensible cooled air passing separately through modular cores withcooling compounded by utilizing multiple stages. As will be described, aportion of the sensibly cooled air from one state is directed throughthe evaporative chamber of another stage that sensibly cools theremaining portion of air from said one stage, with an efficient andpredictable temperature drop in each instance. The numberof stagesemployed is determinative of the total temperature drop, ascircumstances require.

The economical fabrication of heat exchanger cores has been a problem inthe design of condensers and the like, and where high pressures areemployed the tubes extending through fluid handling chambers must bepressure sealed at opposite headers. However, evaporative coolers (notso with mechanical refrigerators) deal with lower pressures wherein itis feasible to employ the press fitting together of plastic and/orelastomeric parts and elements. It is to this end, therefore, that it isan object of this invention to employ a core structure fabricated ofinexpensive plastic materials that are conducive to cleanliness andwhich are not adversely restrictive to the efficient heat transfer.

It is also an object of this invention to provide compatible evaporatorand blower modules that are adapted to be cooperatively combined for themovement of separated columns of evaporative and sensible cooled air.Firstly, it is an evaporative module that is provided with a heattransfer core through which the two columns of air pass in directionsrelative or normal to each other. Secondly, it is a blower module thatis provided with air pump means which transports the air on a singleaxis therefrom. A characteristic feature of the modules is their cubicconfiguration, preferably square, and the total use of space within theconfines of the side walls thereof.

It is still another object of this invention to provide the efficientheat transfer between two columns of air and especially between a columnof evaporatively cooled air and a column of sensibly cooled air. It isthe unobvious effect of efficient heat absorption from the evaporativeprocess when employing tubes of low heat transfer capability throughwhich sensibly cooled air is passed. Since the most restrictive heattransfer rate is that into the sensibly cooled air within the tube, theless restrictive heat transfer rates through the tube core and betweenthe wetted exterior of the tubes and evaporative air are unobviouslynon-restrictive. Therefore, it is in fact feasible to employ inexpensiveplastic tubes of relatively low thermal conductivity as the heatexchange tubes of the cores as they are hereinafter described.

DRAWINGS The various objects and features of this invention will befully understood from the following detailed description of the typicalpreferred form and application thereof, throughout which descriptionreference is made to the accompanying drawings, in which:

FIG. 1 is a perspective view of a typical arrangement of componentscomprising the cooperative combination of evaporator and blower modulesjoined by a diffuser. FIG. 2 is a perspective view of one of theevaporative modules shown in FIG. 1. FIG. 3 is a perspective view of oneof the blower modules shown in FIG. 1. FIG. 4 is an exploded diagram ofthe modules arranged as shown in FIG. 1 and separated in order toillustrate their individuality. FIG. 5 is an elevational sectional viewof the evaporator module taken as indicated by line 5-5 on FIG. 2. FIG.6 is a perspective view of one of the tubes which characterizes theinvention. FIG. 7 is an enlarged fragmentary sectional view taken asindicated by line 77 on FIG. 6. FIG. 8 is an elevational sectional viewof the blower module taken as indicated by line 8-8 on FIG. 3, and FIG.9 is a perspective view similar to FIG. 1 and illustrates a secondembodiment of the invention.

PREFERRED EMBODIMENT The phenomenon of evaporative cooling is a wellknown effect, in which process decrease in energy as a result of airtemperature decrease is regained in the form of moisture; the net resultbeing no change in energy. However, in a sensible cooling process thereis a change in energy (Enthalpy) by not admitting moisture; the netresult being a subtraction of energy from the air. The obviousdisadvantage of ordinary evaporative cooling is the addition of moistureto the useful air, whereas the advantage of sensible cooling is thatthere is no change in absolute humidity during the cooling process ofuseful air. Reference is made to mechanical refrigeration means normallyemployed in sensible cooling processes, and all of which is to becompared with the dry-air evaporative cooler which is the subject ofsaid US. Pat. No. 3,214,936 where there is a separation of air intorefrigerated air subject to evaporation of water and useful air in whichthere is no humidity change, and wherein conventional construction andmaterials are employed.

In accordance with the present invention it is the dryair evaporativeprinciple that is employed, but with improvements relating to efficiencycoupled with economy, and to universal applicability with controlledoutput of useful air. Efficiency and economy is realized by fabricationof inexpensive but effective materials, and controlled applicability isrealized by the cooperation of modules combined as may be required. Itis the volume of air to be processed which varies in requirement witheach installation and which is adapted to by the concept hereindisclosed.

Reference is made to Disclosure Document No. 014607, filed Nov. 6, 1972,and to FIGS. 6 and 7 of the drawings herein, wherein heat transfer tubes10 of plastic material are advantageously employed. It is the unobviousutility of material having low thermal conduc- I tivity as related tothat of the evaporative medium such as water, which neverthelessproduces this efficient and practical sensible cooling system employingthe evaporative cooling principle in the primary cooling process.

The heat transfer tube 10 is a plastic evaporative cooler elementcomprising a heat conductive wall 11, a material such aspolyvinylchloride known as PVC, with one side thereof in contact withthe evaporative medium, such as water, and with the other side thereofin contact with the fluid to be cooled, such as the sensible cooleduseful air. It is the characteristic of this invention that two columnsof fluid are separated by the heat conductive wall 11 having one side toreceive the evaporative medium and give up heat and the other side toreceive or take up heat. The heat conductive wall can be a plate or thelike, in lieu of a tube, and the evaporative outside is surfaced as forexample with gauze 12 as best illustrated in FIG. 7 of the drawings. Thesaid other inside has interfacial contact with the air from which heatis sensibly absorbed. It has been discovered that the use of highlyconductive and expensive materials in the fabrication of the heattransfer wall 11 is quite unnecessary. In other words, the use of metalssuch as copper and aluminum in no way enhances the operation of the heatexchanger wall made thereof when employed in an evaporative cooler ofthe type under consideration where the heat conductivity differential atthe water to material interface is roughly a ratio of 450 to 1. Considertherefore, the following:

THERMAL CONDUCTIVITY OF ELEMENTS Aluminum 135.000 BTU/HR/Sq Ft/F/FtWater .330 Air .160 Water Vapor .137 Polyvinylchloride (PVC) .100

Operation of a conventional cooler with all aluminum tubing wrapped withgauze moistened with water; will produce a 10 to 15 F. temperature dropin a 86 day, with a temperature drop of useful air of 0.4 to 0.5 of thedifference between the inlet and outlet dry-bulb temperatures. Operationof the same cooler with plastic tube made according to this invention ofinch l/l6 inch wall polyvinylchloride (PVC) irrigation pipe also wrappedwith gauze and moistened with water produced the same 10 to 15temperature drop and same 0.4 to 0.5 difference between the inlet andoutlet drybulb temperatures.

Aluminum tubing is costly, while polyvinylchloride (PVC) plastic tube ispresently four times less expensive. The comparison with copper tubingis far more favorable. Consequently, the use of pipe or tubing made ofpolyvinylchloride (PVC) plastic, now readily available, presents newdimensions to the cost structure and potential marketability orusefulness for this plastic fabrication concept.

By way of analogy the following explains the phenomenon employed toadvantage herein: Consider the heat flow rate from air inside of a tube,through the tube and then through a film of water and to the evaporativewater-air interface. This is roughly analogous to a series of flowcontrolling valves; for example, wherein the first valve is a quarterinch valve, the second is a ten inch valve and the third is a one inchvalve. The flow through the quarter inch valve is at a maximum while theflow through the other two valves hardly contributes to the resistance.With this analogy in mind, substitute valves of thermal conductivity forthe flow resistance of each valve given as an example above and it canbe readily concluded that the choke in the heat transfer rate is fromthe air inside of the tube, and this is the controlling factor.Therefore, a superior heat conductivity of the tube is ridiculous andunnecessary.

Referring now to the modules as they are illustrated individually inFIGS. 2 and 3 of the drawings, there is a dry-air evaporative module Xand a blower module Y, the two of which are employed as shown in FIGS. 1and 9; in FIG. 1 as components of a multi-stage cooler, and in FIG. 9 ascomponents of a pre-cooler for a mechanical refrigeration unit R. Themodules X and Y are adapted to be joined one to the other for flow ofair therethrough, and they are adapted to be coupled together by aplenum unit Z. The modules X and Y are three dimensional squares, andthe plenum unit Z is dimensioned accordingly to receive and transportair between the modules coextensively of the cross sections thereof andfrom the open sides and/or open ends. Thus, the modules X and Y areadapted to be placed and/or stacked side by side, end to end, and top tobottom, dependent upon the augmentation required in order to achieve theair delivery capacity desired.

The evaporator module X involves a dry-air evaporative cooler C thatfully occupies the volumetric space between top and bottom panels 15 and16, and in practice there are corner legs 17 that join the panelstogether in spaced parallel planes for receiving and capturing the coreC in working position therebetween. As best illustrated in FIG. 5, thedry-air evaporative cooler core C involves a multiplicity of the tubes10 hereinabove described that extend between headers 18 in which theyare supportably sealed. The headers 18 are identical panels perforatedwith openings 19 into which the opposite end portion 20 of the tubes arepressed. The headers 18 are square panels of deformible material havingtop, bottom and opposite side edges compressed within the confines ofthe panels and 16 and opposite side legs 17 when the core is positioned.Accordingly, the core headers are made of a resiliently compressibleplastic or elastomeric material through which the tubes 10 frictionallyproject with the compression fit assured by the compressed confinementwithin the panels and legs. In practice, the on-center spacing of tubes10, vertically as well as horizontally, is approximately two diameters;in which case there is substantial diagonal clearance between tubes forthe exterior evaporative process when made damp by the application ofwater thereover. Characteristically therefore, the dry-air evaporatormodule X comprises closed top and bottom panels, and open sides and openends through which separate columns of air are free to be transported.The primary cooling process involves evaporative cooling over theexterior of the tubes 10 by air flowing transversely over said tubes;and the secondary cooling process involves sensible cooling within theinterior of the tubes 10 by air flowing longitudinally through saidtubes.

Liquid distributing means B is provided to either wet the air or to wetthe tubes and which can vary as circumstances require. As shown, themeans B involves a liquid carrying conduit 21 disposed above eachvertical arrangement of tubes 10. The conduits 21 are joined by amanifold 22 and they are perforated so as to discharge downwardly ontothe vertical arrangements of tubes. As shown, there is a motor drivenpump 23 that recirculates water from a pan or sump 24 formed of thebottom panel 16, and there is a water level controlled water supplymeans L to maintain water at the desired level in said pan. With thisarrangement the exterior of the evaporative tubes 10 are kept constantlywetted.

The blower module Y involves an air pump means P of any suitable typeand preferably a centrifugal fan comprising a blower scroll 25 withopposite end openings 26 between which a barrel type blower wheel 27 isdisposed on a transverse horizontal shaft 28 about which the rotor of adrive motor 29 driveably revolves said wheel. It is to be understod thatvarious blower and drive arrangements can be employed, including axialflow of fans; any of which will transport air longitudinally through theblower module Y which forms an elongate tunnel having top and bottompanels 31 and 32 and opposite side panels 33 also. In practice, whenemploying a centrifugal blower having a scroll 25, the intake end 34 ofthe module is entirely open into the interior chamber thereof, while thedischarge opening 35 of the scroll is substantially smaller in crosssection than the outlet end 36 of the module; in which case a divergentpassage member 37 couples said discharge opening with said outlet end.Thus, the air delivered by the blower module Y is blown from the entirecross sec tional area thereof defined by the panels 31, 32 and 33.

The evaporator module X is by itself ineffective to deliver useful airand requires air transport means for relative transverse andlongitudinal air flow therethrough. The advantage of the modularconstruction is for adaption to specifications relating to refrigerationor cooling capacity, all of which is readily complied with by employingmultiple combinations of modules X and Y, or a substitute air transportmeans for module Y as shown as a complete mechanical refrigeration unitR in FIG. 9. In any case, separate columns of evaporative cooled air andsensibly cooled useable air are transported under low pressures throughthe modules X at right angles to each other; primary air transverselytherethrough for evaporative cooling over the exterior of tubes 10, andsecondary air longitudinally therethrough for sensible cooling withinthe interior of said tubes. In each instance the blower modules Y are tobe used in transporting the air as clearly shown in FIG. 1.

Referring now to the plenum unit Z, separation of sensibly cooled airfrom the delivery end of an evaporator module X into two columns of airis provided for. This plenum unit can vary widely in design andconfiguration and requires in its broadest sense an inlet 40 and a pairof outlets 41 and 42. The plenum structure is shown as involving top andbottom panels 43 and 44 coplanar with the top and bottom panels ofmodules X and Y to establish imperforate continuations thereof, andimperforate side panels 45 that extend continuously between the sidepanels of said modules. In practice, the plenum is extended laterallybeyond and coextensively over the intake side of the module X into whichit delivers said proportion of sensibly cooled air. The function ofinlet 40 is to receive the total sensibly cooled air delivered by anevaporator module X; the function of outlet 41 is to deliver adetermined portion of said total sensibly cooled air into a second stageevaporator module X for subsequent sensible cooling; and the function ofoutlet 42 is to deliver a determined portion of said total sensiblycooled air into said second stage evaporator module X for subsequentevaporative cooling. The divisible portions of air delivered to outlets41 and 42 can vary as circumstances require dependent upon volume andtemperature drop requirements in each instance. For example, a plenumunit 2 providing for substantially equal distribution is shown in FIG. 1wherein the cross sectional area of outlet 42 represented by the dottedlines is 50 percent of the full cross sectional area of outlet 41represented by dotted lines. Consequently, 50 percent of the total flowof sensibly cooled air represented by arrow a is diverted and dischargedas evaporatively cooled air as represented by the arrow b. The primaryair that is evaporatively cooled moves transversely through the modulesX in each instance, and as represented by the arrow c is the first stageof cooling.

Referring now to compound cooler combinations shown as a typicalembodiment in FIG. 1 of the drawings, there is a separate blower moduleY provided for each individual cooling process represented by the arrowsa, b and c. As shown, the blower modules Y are suction blowers whichdraw the proportionate columns of air as described, the sensibly cooleduseful air being delivered from a blower module Y along arrow a, thedivisible evaporative air being delivered from a blower module Y alongarrow b, and the solely evaporative air being delivered from a blowermodule Y along arrow c. The evaporatively cooled air is discharged toatmosphere in each instance. It will be seen that the staging orcompounding of evaporative refrigeration utilizing sensibly cooled aircan be repeated in order to achieve the temperature drop required in thesensibly cooled useful air delivered along the arrow a.

Referring now to FIG. 9 of the drawings, the mechanical refrigerationunit R is represented as a complete and operable commercially availableunit, commonly designated as an air conditioner." Such a unit R isnormally electrically powered and involves a compressor, an expansionmeans and evaporator for heat absorption, and a condensor means forliquifying the refrigerant for recycling into the compressor etc. Unit Rprovides for the air transport required in the movement of sensiblycooled air through the tubes 10 of evaporator module X, which thencooperatively combines with the unit R as a pre-cooler. Again however,the blower module Y is employed to transport transverse evaporativelycooled air over the tubes 10. This combination provides for the economicfeasibility of pre-cooling air conditioning condensors, so that thecondensor performs as though it were exposed to a lower ambienttemperature day. For example, a 100 day would be reduced to an 85 day,and this allows the condenser to reject 30 percent to 50 percent moreheat. Collectively, this innovation is proposed for incorporationthroughout metrorpolitian areas, in which case the power stations wouldnot see the effects of heat storm peak air conditioning demands, thusproviding energy conservation calculated to reduce the temperature ofmake up air at the rate of about l/lOth the horse power presentlyrequired by mechanical refrigeration. This saving in electrical powerwould obviate the brown and black out problems. The electrical energycapacity previously held in reserve for heat storm periods can then beused productively for other purposes, new growth requirements, etc.

It will be apparent from the foregoing that a most practical and yetless expensive cooling is provided in which the evaporative medium isseparated from the fluid being cooled, and that this process andapparatus made in accordance therewith is useful for purposes other thanthe cooling of air. Further, energy costs for lowering air temperaturemakes feasible the preco oling of air conditioning condensors and thelike, and to the end that there is a substantial conservation of energy.The panels of the evaporative module X are imperforate for the singleheight combinations shown, it being understood that multi-unit heightcombinations of modules X are made with open frame-like panel membersand/or 16; in this way establishing a single air column c-b subject to ablower means. Unobviously, there is an energy change in the primaryevaporatively cooled air c-b, due to the absorption of heat from thesensible cooled air; and it is this semi-cooled air which is dischargedseparately and isolated from the sensibly cooled useful air.

Having described only typical preferred forms and applications of myinvention, I do not wish to be limited or restricted to the specificdetails herein set forth, but wish to reserve to myself anymodifications or variations that may appear to those skilled in the art:

I claim:

1. A dry-air evaporative cooler including: a pair of spaced side membersand a core means having opposite interfaces separating the space betweensaid members into two angularly related air passages with wetting meansat one interface engaging a primary evaporative column of air and withthe other interface engaging a secondary sensible cooled column of airwith heat transfer between said opposite interfaces, the remaining twopairs of opposite sides between said members being open therebetween forsaid angularly related movement of said separate columns of air, andboth said separate columns of air being moveable through said twoangularly related passages coextensively between the said spacedmembers.

2. The dry-air evaporative cooler as set forth in claim 1 wherein thepair of spaced side members are of square configuration and spaceddimensionally equal to said squareness.

3. The dry-air evaporative cooler as set forth in claim 1 wherein thecore means is comprised of a multiplicity of spaced parallel tubesextending between opposite end headers coextensively between said pairof spaced side members.

4. The dry-air evaporative cooler as set forth in claim 1 wherein thecore means is comprised of a multiplicity of spaced parallel tubesextending between opposite end headers coextensively between saidspa'ced members and wherein the wetting means is at the exteriorinterface of said tubes.

5. The dry-air evaporative cooler as set forth in claim 1 wherein thecore means is comprised of spaced opposite end headers of resilientlydeformible material extending coextensively between said spaced membersin and between which spaced parallel tubes are supported in friction fitopenings.

6. The dry-air evaporative cooler as set forth in claim 1 wherein thecore means is comprised of spaced opposite end headers of elastomericmaterial extending coextensively between said spaced members in andbetween which spaced parallel tubes are supported in friction fitopenings.

7. The dry-air evaporative cooler as set forth in claim 1 wherein thecore means is comprised of a multiplicity of spaced parallel tubes ofplastic material extending between opposite end headers coextensivelybetween said spaced members.

8. The dry-air evaporative cooler as set forth in claim 1, wherein thecore means is comprised of a multiplicity of spaced parallel tubes ofplastic material extending between opposite end headers coextensivelybetween said spaced members, and wherein the wetting means is gauzewrapping at the exterior interfaces of said tubes.

9. The dry-air evaporative cooler as set forth in claim 1, wherein thecore means is comprised of opposite end headers of elastomeric materialextending coextensively between said spaced members in and between whichspaced parallel tubes of plastic material are supported in friction fitopenings, and wherein the wetting means is gauze wrapping at theexterior interfaces of said plastic tubes.

10. A dry-air evaporative cooler including;

an evaporator module comprised of spaced members and a core means havingopposite interfaces separating the space between said members into twoangularly related air passages with wetting means at one interfaceengaging a primary evaporative column of air and with the otherinterface engaging a secondary sensible cooled column of air with heattransfer between said opposite interfaces, both said separate columns ofair being moveable through said two angularly related passagescoextensively between the said spaced members, and a pair of like blowermodules and each comprising means drawing air through one of saidangularly related air passages coextensively between said members.

11. The dry-air evaporative cooler combined of modules as set forth inclaim 10, wherein the members are of rectangular configuration, andwherein the remaining two pairs of opposite sides between said membersare open therebetween for said angularly related movement of saidseparate columns of air through said pair of like blower modulesrespectively.

12. The dry-air evaporative cooler combined of modules as set forth inclaim 10, wherein the members are of squared configuration and spaceddimensionally equal to said squareness, and wherein the remaining twopairs of opposite sides between said members are open therebetween forsaid angularly related movement of said separate columns of air throughsaid pair of like blower modules respectively.

13. The dry-air evaporative cooler combined of modules as set forth inclaim 10, wherein the core means is comprised of a multiplicity ofspaced parallel tubes extending between opposite end headerscoextensively between said spaced members, wherein the members are ofrectangular configuration, and wherein the remaining two pairs ofopposite sides between said members are open therebetween for saidangularly related movement of said separate columns of air through saidpair of like blower modules respectively.

14. The dry-air evaporative cooler combined of modules as set forth inclaim 10, wherein the core means is comprised of a multiplicity ofspaced parallel tubes extending between opposite end headerscoextensively between said spaced members, wherein the members are ofsquared configuration and spaced dimensionally equal to said squareness,and wherein the remaining two pairs of opposite sides between saidmembers are open therebetween for said angularly related movement ofsaid separate columns of air through said pair of like blower modulesrespectively.

15. A compound dry-air evaporative cooler including; a pair ofevaporator modules and each comprised of a core means having oppositeinterfaces establishing two air passages with wetting means at oneinterface engaging a primary evaporataive column of air and with theother interface engaging a secondary sensible cooled column of air withheat transfer between said opposite interfaces, both said separatecolumns of air being moveable by blower means through said two angularlyrelated passages, and a diffuser means dividing the secondary sensiblecooled column of air from one evaporator module and delivering separateprimary and secondary columns of air through the respectivelycomplementary passages therefor of the other evaporator module, therebyeffecting a second stage of sensible cooling with cooled dry evaporativeair.

16. The compound dry-air evaporator cooler as set forth in claim whereinseparate blower means moves the separate primary evaporative columns ofair through each of the pair of evaporator modules respectively.

17. The compound dry-air evaporator cooler as set forth in claim 15wherein separate blower means moves the secondary sensible cooled columnof air through the pair of evaporator modules.

18. The compound dry-air evaporator cooler as set forth in claim 15,wherein separate blower means moves the secondary sensible cooled columnof air through the pair of evaporator modules, and wherein separateblower means moves the separate primary evaporative columns of airthrough each of the pair of evaporator modules respectively.

19. The compound dry-air evaporator cooler as set forth in claim 15wherein the diffuser means comprises a full flow intake from said oneevaporator module and a restrictive outlet into at least one passage ofsaid other evaporator module.

20. A dry-air evaporator pre-cooler for mechanical refrigeration means,and including; a core means having opposite interfaces establishing twoair passages with wetting means at one interface engaging a primaryevaporative column of air and with the other interface engaging asecondary sensible cooled column of air with heat transfer between saidopposite interfaces, blower means moving the primary evaporative columnof air through said passage therefor, and the mechanical refrigerationmeans having a condensor and an air blower means with an intake drawingthe secondary sensible cooled column of air through said condensor fromthe passage therefor, whereby said mechanical refrigeration condensoroperates with sensible cooled air at a substantially reduced intaketemperature.

21. The dry-air evaporative pre-cooler as set forth in claim 20 whereinthe intake drawing of the secondary sensible cooled column of airthrough the pre-cooler passage therefor is directed through heatabsorption means of said mechanical refrigeration means.

22. The dry-air evaporative pre-cooler as set forth in claim 20 whereinthe intake drawing of the secondary sensible cooled column of airthrough the pre-cooler passage therefor is directed through sensiblecooling means of said mechanical refrigeration means.

23. The dry-air evaporative pre-cooler as set forth in claim 20 whereinthe intake drawing of the secondary sensible cooled column of airthrough the pre-cooler passage therefor is directed through both thesensible cooling means and said heat absorption means of said mechanicalrefrigeration means.

1. A dry-air evaporative cooler including: a pair of spaced side membersand a core means having opposite interfaces separating the space betweensaid members into two angularly related air passages with wetting meansat one interface engaging a primary evaporative column of air and withthe other interface engaging a secondary sensible cooled column of airwith heat transfer between said opposite interfaces, the remaining twopairs of opposite sides between said members being open therebetween forsaid angularly related movement of said separate columns of air, andboth said separate columns of air being moveable through said twoangularly related passages coextensively between the said spacedmembers.
 2. The dry-air evaporative cooler as set forth in claim 1wherein the pair of spaced side members are of square configuration andspaced dimensionally equal to said squareness.
 3. The dry-airevaporative cooler as set forth in claim 1 wherein the core means iscomprised of a multiplicity of spaced parallel tubes extending betweenopposite end headers coextensively between said pair of spaced sidemembers.
 4. The dry-air evaporative cooler as set forth in claim 1wherein the core means is comprised of a multiplicity of spaced paralleltubes extending between opposite end headers coextensively between saidspaced members and wherein the wetting means is at the exteriorinterface of said tubes.
 5. The dry-air evaporative cooler as set forthin claim 1 wherein the core means is comprised of spaced opposite endheaders of resiliently deformible material extending coextensivelybetween said spaced members in and between which spaced parallel tubesare supported in friction fit openings.
 6. The dry-air evaporativecooler as set forth in claim 1 wherein the core means is comprised ofspaced opposite end headers of elastomeric material extendingcoextensively between said spaced members in and between which spacedparallel tubes are supported in friction fit openings.
 7. The dry-airevaporative cooler as set forth in claim 1 wherein the core means iscomprised of a multiplicity of spaced parallel tubes of plastic materialextending between opposite end headers coextensively between said spacedmembers.
 8. The dry-air evaporative cooler as set forth in claim 1,wherein the core means is comprised of a multiplicity of spaced paralleltubes of plastic material extending between opposite end headerscoextensively between said spaced members, and wherein the wetting meansis gauze wrapping at the exterior interfaces of said tubes.
 9. Thedry-air evaporative cooler as set forth in claim 1, wherein the coremeans is comprised of opposite end headeRs of elastomeric materialextending coextensively between said spaced members in and between whichspaced parallel tubes of plastic material are supported in friction fitopenings, and wherein the wetting means is gauze wrapping at theexterior interfaces of said plastic tubes.
 10. A dry-air evaporativecooler including; an evaporator module comprised of spaced members and acore means having opposite interfaces separating the space between saidmembers into two angularly related air passages with wetting means atone interface engaging a primary evaporative column of air and with theother interface engaging a secondary sensible cooled column of air withheat transfer between said opposite interfaces, both said separatecolumns of air being moveable through said two angularly relatedpassages coextensively between the said spaced members, and a pair oflike blower modules and each comprising means drawing air through one ofsaid angularly related air passages coextensively between said members.11. The dry-air evaporative cooler combined of modules as set forth inclaim 10, wherein the members are of rectangular configuration, andwherein the remaining two pairs of opposite sides between said membersare open therebetween for said angularly related movement of saidseparate columns of air through said pair of like blower modulesrespectively.
 12. The dry-air evaporative cooler combined of modules asset forth in claim 10, wherein the members are of squared configurationand spaced dimensionally equal to said squareness, and wherein theremaining two pairs of opposite sides between said members are opentherebetween for said angularly related movement of said separatecolumns of air through said pair of like blower modules respectively.13. The dry-air evaporative cooler combined of modules as set forth inclaim 10, wherein the core means is comprised of a multiplicity ofspaced parallel tubes extending between opposite end headerscoextensively between said spaced members, wherein the members are ofrectangular configuration, and wherein the remaining two pairs ofopposite sides between said members are open therebetween for saidangularly related movement of said separate columns of air through saidpair of like blower modules respectively.
 14. The dry-air evaporativecooler combined of modules as set forth in claim 10, wherein the coremeans is comprised of a multiplicity of spaced parallel tubes extendingbetween opposite end headers coextensively between said spaced members,wherein the members are of squared configuration and spaceddimensionally equal to said squareness, and wherein the remaining twopairs of opposite sides between said members are open therebetween forsaid angularly related movement of said separate columns of air throughsaid pair of like blower modules respectively.
 15. A compound dry-airevaporative cooler including; a pair of evaporator modules and eachcomprised of a core means having opposite interfaces establishing twoair passages with wetting means at one interface engaging a primaryevaporataive column of air and with the other interface engaging asecondary sensible cooled column of air with heat transfer between saidopposite interfaces, both said separate columns of air being moveable byblower means through said two angularly related passages, and a diffusermeans dividing the secondary sensible cooled column of air from oneevaporator module and delivering separate primary and secondary columnsof air through the respectively complementary passages therefor of theother evaporator module, thereby effecting a second stage of sensiblecooling with cooled dry evaporative air.
 16. The compound dry-airevaporator cooler as set forth in claim 15 wherein separate blower meansmoves the separate primary evaporative columns of air through each ofthe pair of evaporator modules respectively.
 17. The compound dry-airevaporator cooler as set forth in claim 15 wherein separate blower meansmoves the secondary sensiblE cooled column of air through the pair ofevaporator modules.
 18. The compound dry-air evaporator cooler as setforth in claim 15, wherein separate blower means moves the secondarysensible cooled column of air through the pair of evaporator modules,and wherein separate blower means moves the separate primary evaporativecolumns of air through each of the pair of evaporator modulesrespectively.
 19. The compound dry-air evaporator cooler as set forth inclaim 15 wherein the diffuser means comprises a full flow intake fromsaid one evaporator module and a restrictive outlet into at least onepassage of said other evaporator module.
 20. A dry-air evaporatorpre-cooler for mechanical refrigeration means, and including; a coremeans having opposite interfaces establishing two air passages withwetting means at one interface engaging a primary evaporative column ofair and with the other interface engaging a secondary sensible cooledcolumn of air with heat transfer between said opposite interfaces,blower means moving the primary evaporative column of air through saidpassage therefor, and the mechanical refrigeration means having acondensor and an air blower means with an intake drawing the secondarysensible cooled column of air through said condensor from the passagetherefor, whereby said mechanical refrigeration condensor operates withsensible cooled air at a substantially reduced intake temperature. 21.The dry-air evaporative pre-cooler as set forth in claim 20 wherein theintake drawing of the secondary sensible cooled column of air throughthe pre-cooler passage therefor is directed through heat absorptionmeans of said mechanical refrigeration means.
 22. The dry-airevaporative pre-cooler as set forth in claim 20 wherein the intakedrawing of the secondary sensible cooled column of air through thepre-cooler passage therefor is directed through sensible cooling meansof said mechanical refrigeration means.
 23. The dry-air evaporativepre-cooler as set forth in claim 20 wherein the intake drawing of thesecondary sensible cooled column of air through the pre-cooler passagetherefor is directed through both the sensible cooling means and saidheat absorption means of said mechanical refrigeration means.